BuddyPress.org

Seems simple enough. You can disable a lot of the functionality you don’t want in the admin.

The custom parts will be the profile itself, but you should be able to do this pretty nicely using the xProfile fields without too much custom work on your end. You might also have to build a custom search to search through those profile fields, but there are a number of plugins you can look at to build out that functionality.

I’d consider using s2member as the payment method for people signing up. That should work for what you want I think.

As a side note, I’ve created a sports website that teams can use to fundraise called Giving Sports: http://givingsports.com Athlete profiles is not the core of the site, but each athlete just gets a profile as a means to fundraise for their team. It will be interesting to see how that evolves over time since athlete profiles are valuable and interesting.